The skin acts as the body's first line of defense against infection. However, the skin can become irritated and loose its ability to defend against infection by continual exposure to proteases. For example, it was once believed that contacting the skin with urine produced diaper rash. However, it is now understood that the irritation of tissue that manifests itself in “diaper rash” is primarily caused by proteolytic and/or lipolytic enzymes that are present in human feces, for example, trypsin, chymotrypsin, elastase, and pancreatic lipase. Moreover, the causes of skin irritation are not limited to enzymes present in feces. Other biological materials including, for example, menstrual fluids, nasal fluids, colostomy fluids, dandruff, wound healing may all provide a source of enzymes that produce skin irritation.
While some proteolytic and lipolytic enzyme inhibitors are known, they often have short-lived effects and/or can irritate skin and other tissues. Hence, compositions containing naturally-occurring, stable and non-irritating protease inhibitors are needed for use in personal care items such as diapers, tampons and feminine care pads.